In some instances of erectile impotence in which the patient does not respond to more conventional therapy, the surgical implanting of a penile prosthesis may be the only practical means of remedying the impotency.
In the past, several types of penile prostheses have been employed. The first type is a rod of suitable stiffness which is surgically implanted into the corpus cavernosum of the penis. The major disadvantage of the rod-type implant is the permanent stiffness of the rod which can be a source of physical pain as well as embarrassment to the patient. The rod-type prostheses disclosed in U.S. Pat. Nos. 3,853,122 and 4,066,073 are attempts to overcome that disadvantage.
The other type of penile prosthesis which is available is the inflatable prosthesis. The most common inflatable prosthesis includes two fairly long inflatable tubes that are surgically implanted in the corpus cavernosum of the penis. Each of the two tubes is connected by tubing to a pressure bulb of inflating fluid which is implanted elsewhere in the body. Because of the volume required to pressurize and rigidize the inflatable tubes, the pressure bulbs are relatively large. In the prosthesis of U.S. Pat. No. 3,954,102 the fluid is supplied from a single relatively large reservoir which is implanted in the abdominal cavity.
The inflatable penile prosthesis of U.S. Pat. No. 4,009,711 includes two implants each having its own relatively large pressurizing bulb which is surgically implanted in the scrotal sac. The penile implant includes a non-distensible stem portion made of a relatively stiff silastic material which supports the implant and an integral collapsible bag-like distensible portion which is implanted into the cavernosum of the pendulus penis.
Inflatable implants currently available must be inflated periodically to prevent the scar tissue capsule which forms about the implant from bridging folds in the fabric of the inflatable or distensible portion and preventing the implant from becoming fully inflated.